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PT. Metro Batavia Airline PK–YTU
Boeing Company 737-300Depati Amir Airport, Pangkal Pinang
Republic of Indonesia
7 January 2007
Aircraft Serious Incident Investigation
NATIONAL TRANSPORTATION SAFETY COMMITTEE MINISTRY OF TRANSPORTATION REPUBLIC OF INDONESIA 2010
This Final Report was produced by the National Transportation Safety Committee (NTSC), Karya Building 7th Floor Ministry of Transportation, Jalan Medan Merdeka Barat No. 8 Jakarta 10110, Indonesia.
The report is based upon the investigation carried out by the NTSC in accordance with Annex 13 to the Convention on International Civil Aviation, the Indonesian Aviation Act (UU No. 1/2009) and Government Regulation (PP No. 3/2001).
Readers are advised that the NTSC investigates for the sole purpose of enhancing aviation safety. Consequently, the NTSC reports are confined to matters of safety significance and may be misleading if used for any other purpose.
As the NTSC believes that safety information is of greatest value if it is passed on for the use of others, readers are encouraged to copy or reprint for further distribution, acknowledging the NTSC as the source.
When the NTSC makes recommendations as a result of its investigations or research, safety is its primary consideration.
However, the NTSC fully recognizes that the implementation of recommendations arising from its investigations will in some cases incur a cost to the industry.
Readers should note that the information in NTSC reports and recommendations is provided to promote aviation safety. In no case is it intended to imply blame or liability.
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TABLE OF CONTENTS TABLE OF CONTENTS ..................................................................................................... i
TABLE OF FIGURES ....................................................................................................... iii
GLOSSARY OF ABBREVIATIONS ................................................................................ v
INTRODUCTION ............................................................................................................... 1
1 FACTUAL INFORMATION...................................................................................... 3 1.1 History of the Flight............................................................................................ 3
1.2 Injuries to Persons............................................................................................... 4
1.3 Damage to Aircraft ............................................................................................. 4
1.4 Other Damage..................................................................................................... 4
1.5 Personnel Information ........................................................................................ 5
1.5.1 Pilot in command................................................................................... 5
1.5.2 Co-pilot.................................................................................................. 5
1.6 Aircraft Information............................................................................................ 5
1.6.1 General .................................................................................................. 5
1.6.2 Nose Landing Gear Information............................................................ 6
1.6.3 Maintenance Data .................................................................................. 6
1.7 Meteorological Information................................................................................ 6
1.8 Aids to Navigation.............................................................................................. 6
1.9 Communications ................................................................................................. 6
1.10 Aerodrome Information ...................................................................................... 6
1.11 Flight Recorders.................................................................................................. 7
1.12 Wreckage and Impact Information ..................................................................... 7
1.13 Medical and Pathological Information ............................................................... 7
1.14 Fire...................................................................................................................... 7
1.15 Survival Aspects ................................................................................................. 7
1.16 Tests and Research ............................................................................................. 7
1.17 Organisational and Management Information .................................................... 7
1.18 Additional Information ....................................................................................... 7
1.18.1 Laboratory Examination........................................................................ 7
1.18.2 Line Maintenance Finding..................................................................... 8
1.19 Useful or Effective Investigation Techniques .................................................... 8
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2 ANALYSIS ....................................................................................................................9 2.1 Failure Analysis ..................................................................................................9
2.2 Maintenance Practice ..........................................................................................9
3 CONCLUSIONS .........................................................................................................11 3.1 Findings.............................................................................................................11
3.2 Causes ...............................................................................................................11
4 SAFETY ACTIONS AND RECOMMENDATIONS..............................................13 4.1 Safety Actions ...................................................................................................13
4.2 Recommendations.............................................................................................13
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TABLE OF FIGURES Figure 1: The Boeing B737-300 aircraft Reg. PK-YTU after occurrence .............................3
Figure 2: Damaged on the right nose wheel axle shaft...........................................................4
Figure 3: The right nose wheel axle shaft and the right nose wheel .....................................4
Figure 4: Overload forces indicated by beach marks .............................................................8
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GLOSSARY OF ABBREVIATIONS AFML : Aircraft Flight Maintenance Log AOC : Air Operator Certificate ATPL : Air Transport Pilot License CASR : Civil Aviation Safety Regulation CPL : Commercial Pilot License CVR : Cockpit Voice Recorder DGCA : Directorate General Civil Aviation FDR : Flight Data Recorder ITB : Institute of Technology, Bandung NDT : Non-Destructive Test KNKT / NTSC : Komite Nasional Keselamatan Transportasi / National Transportation Safety Committee PIC : Pilot in Command UTC : Universal Time Coordinate
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INTRODUCTION
SYNOPSIS
On 7 January 2007, a Boeing Company 737-300 aircraft, operated by Metro Batavia Airline (Batavia Air), registered PK-YTU, was on a scheduled passenger service as flight number 7P-524 from Depati Amir Airport, Pangkal Pinang1 with intended destination was Soekarno-Hatta Airport, Jakarta.
At 10:00, the aircraft was lining up by turning 180º, while the aircraft turn 90º, the pilot heard a sound, he assumed that its came from something that was braking. The pilot decided to return to apron for inspection to the source of the sound.
After inspection, it was found that right nose wheel axle shaft was broken and right nose wheel was missing.
The right nose wheel axle shaft and the nose wheel were found on runway shoulder approximately 3 meters from the runway.
The metallurgy laboratory of the ITB investigation report concluded that the initial crack of the lower of the right nose wheel axle shaft, it was indicated of overloaded forces, at ten time of landing before occurrence as indicated by beach mark.
During the investigation the Operator and DGCA took safety action:
a. Conducting of inspection to all B737 fleet against the possibility similar damage with NDT methods.
b. Quality Assurance Department had reviewed/evaluated and trained all ratings holders to improve their knowledge of the standard basic of aircraft maintenance.
c. Department of Engineering had reviewed/evaluated to all AMM that used for maintenance on its validity and currency.
1 Depati Amir Airport, Pangkal Pinang is referred as ‘Pangkal Pinang’ in this report.
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1 FACTUAL INFORMATION
1.1 History of the Flight
On 7 January 2007, a Boeing Company 737-300 aircraft, operated by Metro Batavia Airline (Batavia Air), registered PK-YTU, was on a scheduled passenger service as flight number 7P-524 from Depati Amir Airport, Pangkal Pinang with intended destination was Soekarno-Hatta Airport, Jakarta. The flight carried 142 passengers including 3 infants, and 6 crewmembers consist of two pilots and four flight attendants. The pilot in command (PIC) was the handling pilot, and the co-pilot was the pilot monitoring.
The aircraft block off at 09:57 UTC (16:57 LT) and taxi to runway 16 for take-off.
At 10:00, the aircraft was lining up by turning 180º, while the aircraft turn 90º, the pilot heard a sound, he assumed that its came from something was braking. The pilot decided to return to apron for inspection to the source of the noise.
After inspection, it was found that right nose wheel axle shaft was broken and right nose wheel was missing.
The right nose wheel axle shaft and the nose wheel were found on runway shoulder approximately 3 meters from the runway.
Figure 1: The Boeing B737-300 aircraft Reg. PK-YTU after occurrence
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1.2 Injuries to Persons
1.3 Damage to Aircraft
The right nose wheel axle shaft broken.
Figure 2: Damaged on the right nose wheel axle shaft
Figure 3: The right nose wheel axle shaft and the right nose wheel
1.4 Other Damage There was no other damage to property and/or the environment.
Injuries Flight crew Passengers Total in Aircraft
Others
Fatal - - - - Serious - - - - Minor/None 6 142 148 - TOTAL 6 142 148 -
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1.5 Personnel Information
1.5.1 Pilot in command
1.5.2 Co-pilot Date of birth : 7 May 1979 Gender : Male Nationality : Indonesia Licence : CPL Valid To : 30 April 2007 Type Rating : B737-300/400/500 Date of Medical : 16 October 2006 The pilots held valid licenses and ratings for the operation of the aircraft. This section covering flight crew is not relevant to this serious incident.
1.6 Aircraft Information 1.6.1 General
Date of birth : 23 May 1973 Gender : Male Nationality : Indonesia Licence : ATPL Valid To : 30 April 2007 Type Rating : B737-200/300/400/500 Date of Medical : 30 October 2006 The pilots held valid licenses and ratings for the operation of the aircraft. This section covering flight crew is not relevant to this serious incident.
Aircraft Registration : PK-YTU
Country of Manufacturer : United State of America
Manufacturer : Boeing Company
Type/ Model : B737-300
Serial Number : 25604 Year of Manufacture : 1992 Certificate of Airworthiness Valid to : 2 April 2007
Time Since New : 36,154 hours (1 January 2007)
Cycles Since New : 25,873 cycles (1 January 2007)
Last minor check A11 : 35,996 hours /11 December 2006
At the time of the serious incident, the aircraft was certified as being airworthy.
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1.6.2 Nose Landing Gear Information Part number : 65-73762-21 Serial number : T5050P2339
Last overhaul : 15 July 2002 (FAA No. XYJY995L)
Time between overhaul : 12,903 hours (1 January 2007)
1.6.3 Maintenance Data
Last installation of the nose wheel was on 25 December 2006 (ref. AFML No. 04154).
The right nose wheel axle shaft broken was a part of inner cylinder assembly part number 65-46215-21 serial number CPT2934ET, reaming to life limit was 49,661 cycles and 12,903 hours for overhaul.
1.7 Meteorological Information Not relevant to this serious incident.
1.8 Aids to Navigation Not relevant to this serious incident.
1.9 Communications Communications between the ATC and the crew were normal and no communication difficulty.
1.10 Aerodrome Information Aerodrome Code : PGK / WIPK Airport Name : DEPATI AMIR Airport Address : Jl. Soekarno Hatta / Jl. Koba Km.7
Pangkalan Baru - Pangkal Pinang Airport Class : II Airport Authority : Directorate General of Civil Aviation Airport Service : Domestic Coordinates : 02° 09′ 45′′ S, 106° 08′ 17′′ E Elevation : 109 feet Runway Length : 2,000 meters Runway Width : 30 meters
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1.11 Flight Recorders The aircraft was equipped with Digital Flight Data Recorder (DFDR) and a Cockpit Voice Recorder (CVR).
The flight recorders were quarantined by the National Transportation Safety Committee investigators. The Cockpit Voice Recorder data was downloaded for the investigation. FDR and CVR data were considered not required for the investigation.
1.12 Wreckage and Impact Information
Not relevant to this serious incident.
1.13 Medical and Pathological Information
Not relevant to this serious incident.
1.14 Fire There was no pre or post impact fire.
1.15 Survival Aspects
The pilot and passengers were not injured.
1.16 Tests and Research Not relevant to this serious incident.
1.17 Organisational and Management Information
Aircraft Owner : AerCo Limited 22 Greenville Street, St. Helier, Jersey, JE48PX, Channel Island
Aircraft Operator : PT. Metro Batavia Airline (Batavia Air) Jl. Ir. H. Juanda No. 15 Jakarta Pusat, Republic Indonesia
Air Operator Certificate Number: AOC/121-007
1.18 Additional Information
1.18.1 Laboratory Examination
A metallurgical laboratory examination was performed on the broken axle at the laboratory of metallurgical engineering of the Institute of Technology, Bandung (ITB) under supervision National Transportation Safety Committee (NTSC) investigators. This examination was to determine the cause of the failure of the axle.
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The examination concluded that the initial crack of the lower part of the right nose wheel axle shaft was indication of overloaded forces which initiated ten landings before occurrence as indicated by the beach marks.
Figure 4: Overload forces indicated by beach marks
1.18.2 Line Maintenance Finding
During the course of investigation, it was found the replacement of the broken axle, the replacement was referring to the Aircraft Maintenance Manual that was not applicable to the specific aircraft.
There was a torque meter available without a valid calibration. However, the installation of torque link did not used the torque meter. The engineer assumed that an installation torque link bolt and nut combine with split pin was not required torque value.
1.19 Useful or Effective Investigation Techniques The investigation is being conducted in accordance with the NTSC approved policies and procedures, and in accordance with the standards and recommended practices of Annex 13 to the Chicago Convention.
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2 ANALYSIS
2.1 Failure Analysis
On the nose wheel axle and inner cylinder assembly found an indication of a vertical facture and there was no sign of scratches on the broken nose wheel axle, meanwhile there was no indication of damage on the right nose wheel bearings.
The metallurgy examination found that the failure was due to high load impact indicated by beach mark that was initiated about ten landings prior to occurrence.
The last nose wheel replacement (right and left) was performed on 25 December 2006 and for the last three months there was no complaint related to the nose wheel.
The cylinder assembly has 49,661 cycles and 12,903 hrs for the next scheduled overhaul.
2.2 Maintenance Practice During the course of investigation, it was found the replacement of the broken axle was referring to the Aircraft Maintenance Manual that was not applicable to the specific aircraft. This might lead to incorrect sequence of task, torque value, etc.
There was a torque meter available without a valid calibration. However, the installation of torque link did not used the torque meter. The engineer assumed that an installation torque link bolt and nut combine with split pin was not required torque value.
Installation of torque link without measuring torque value of bolt and nut might caused the torque link too stiff if the torque value is exceed the correct value and may caused an excessive gap on the torque link and may caused nose wheel vibration.
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3 CONCLUSIONS
3.1 Findings On the nose wheel axle and inner cylinder assembly found an indication of a vertical facture and there was no sign of scratches on the broken nose wheel axle, meanwhile there was no indication of damage on the right nose wheel bearings.
The metallurgy examination found that the failure was due to high load impact indicated by beach mark that was initiated about ten landings prior to occurrence.
3.2 Causes The metallurgy examination found that the failure was due to high load impact indicated by beach mark that was initiated about ten landings prior to occurrence.
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4 SAFETY ACTIONS AND RECOMMENDATIONS
4.1 Safety Actions On 10 January 2007, the DGCA issued safety actions for Metro Batavia Airline as follows:
a. Conducted inspection to all Boeing 737 fleet for the possibility of similar damage with Non-Destructive Test (NDT) methods.
b. Quality Assurance Department of Metro Batavia Airline has reviewed, evaluated and trained all aircraft maintenance license hold Boeing 737 rating to improve the knowledge and the standard basic of aircraft maintenance.
c. Engineering Department of Metro Batavia Airline has reviewed and evaluated validity and currency of Aircraft Maintenance Manual (AMM).
4.2 Recommendations
During investigation process the NTSC found important findings that required attention to prevent similar occurrence in the future.
The NTSC recommended to the PT. Metro Batavia Airline should:
a. Conduct inspection to all Boeing 737 fleet for the possibility of similar damage with Non-Destructive Test (NDT) methods.
b. Evaluate and train all aircraft maintenance license hold Boeing 737 rating to improve the knowledge and the standard basic of aircraft maintenance.
c. Review and evaluate validity and currency of Aircraft Maintenance Manual (AMM).
